Indicator not plotting within it's own TimeFrame

This indicator calculates only the timeframes of the higher series instead of the current Timeserie. What am I missing here?

using System;
using cAlgo.API;
using cAlgo.API.Internals;
using cAlgo.API.Indicators;

namespace cAlgo
{
    [Indicator(IsOverlay = true, TimeZone = TimeZones.UTC, AccessRights = AccessRights.None)]
    public class Scalp : Indicator
    {
        [Output("Ema", LineColor = "white", Thickness =5)]
        public IndicatorDataSeries Ema { get; set; }

        private ExponentialMovingAverage _ema;
        TimeFrame _biggerTimeFrame;
        MarketSeries _biggerSeries;

        protected override void Initialize()
        {
            _biggerSeries = MarketData.GetSeries(TimeFrame.Minute15);
            _ema = Indicators.ExponentialMovingAverage(_biggerSeries.Close, 15);
        }

       public override void Calculate(int index)
        {
            int Bigindex = GetIndexByDate(_biggerSeries, MarketSeries.OpenTime[index]);
            if (Bigindex != -1)
            {
                Ema[index] = _ema.Result[Bigindex];
                Print(MarketSeries.TimeFrame, " ", MarketSeries.OpenTime[index], " ", _biggerSeries.TimeFrame, " ", _biggerSeries.OpenTime[Bigindex], " ", index, " ", Bigindex, " ", _ema.Result[Bigindex]);
            }
        }
        private int GetIndexByDate(MarketSeries series, DateTime time)
        {
            for (int i = series.Close.Count - 1; i > 0; i--)
            {
                if (time == series.OpenTime[i])
                    return i;
            }
            return -1;
        }
    }
}

Gives:

and the log is:

26/03/2019 09:36:24.580 | Minute 3/26/2019 9:30:00 AM Minute15 3/26/2019 9:30:00 AM 2753 8585 145.310173787739
26/03/2019 09:36:24.580 | Minute 3/26/2019 9:15:00 AM Minute15 3/26/2019 9:15:00 AM 2738 8584 145.317484328844
26/03/2019 09:36:24.580 | Minute 3/26/2019 9:00:00 AM Minute15 3/26/2019 9:00:00 AM 2723 8583 145.298410661536
26/03/2019 09:36:24.580 | Minute 3/26/2019 8:45:00 AM Minute15 3/26/2019 8:45:00 AM 2708 8582 145.302612184613